diff --git a/include/wabt/stream.h b/include/wabt/stream.h
index 3b68ac8a0..67f50975e 100644
--- a/include/wabt/stream.h
+++ b/include/wabt/stream.h
@@ -195,36 +195,6 @@ class MemoryStream : public Stream {
   std::unique_ptr<OutputBuffer> buf_;
 };
 
-class MemoryAllocStream : public wabt::Stream {
- public:
-  typedef void* (*wabt_realloc)(void* __ptr, size_t __size);
-
-  MemoryAllocStream(uint8_t* _output_data = nullptr,
-                    size_t _total_size = 0,
-                    wabt_realloc _realloc_fn = nullptr)
-      : output_data(_output_data), total_size(_total_size), used_size(0) {
-    if (_realloc_fn) {
-      realloc_fn = _realloc_fn;
-    } else {
-      realloc_fn = std::realloc;
-    }
-  }
-
-  wabt::Result WriteDataImpl(size_t dst_offset, const void* src, size_t size);
-
-  wabt::Result MoveDataImpl(size_t dst_offset, size_t src_offset, size_t size);
-
-  wabt::Result TruncateImpl(size_t size);
-  inline size_t GetSize() const { return used_size; }
-  inline uint8_t* GetData() { return output_data; }
-
- private:
-  uint8_t* output_data;
-  size_t total_size;
-  size_t used_size;
-  wabt_realloc realloc_fn;
-};
-
 class FileStream : public Stream {
  public:
   WABT_DISALLOW_COPY_AND_ASSIGN(FileStream);
diff --git a/src/binary-reader.cc b/src/binary-reader.cc
index 4faa8522e..9ff79ec7c 100644
--- a/src/binary-reader.cc
+++ b/src/binary-reader.cc
@@ -1941,12 +1941,18 @@ Result BinaryReader::ReadInstructions(Offset end_offset, const char* context) {
 }
 
 Result BinaryReader::ReadSkippedFunctionBody(Offset end_offset) {
+#ifdef WABT_KEEP_OPCODE_WHEN_SKIP_FUNC_BODY
   std::vector<uint8_t> opcode_buffer;
   opcode_buffer.resize(end_offset - state_.offset);
   memcpy(opcode_buffer.data(), state_.data + state_.offset,
          opcode_buffer.size());
   CALLBACK(OnSkipFunctionBodyExpr, opcode_buffer);
   state_.offset = end_offset;
+#else
+  // old version with OnEndExpr
+  state_.offset = end_offset;
+  CALLBACK0(OnEndExpr);
+#endif
 
   return Result::Ok;
 }
@@ -2899,12 +2905,7 @@ Result BinaryReader::ReadCodeSection(Offset section_size) {
     CALLBACK(EndLocalDecls);
 
     if (options_.skip_function_bodies) {
-#ifdef WABT_KEEP_OPCODE_WHEN_SKIP_FUNC_BODY
       CHECK_RESULT(ReadSkippedFunctionBody(end_offset));
-#else
-      state_.offset = end_offset;
-      CALLBACK0(OnEndExpr);
-#endif
     } else {
       CHECK_RESULT(ReadFunctionBody(end_offset));
     }
diff --git a/src/stream.cc b/src/stream.cc
index 122c0d7e3..5f27e01b2 100644
--- a/src/stream.cc
+++ b/src/stream.cc
@@ -229,71 +229,6 @@ Result MemoryStream::TruncateImpl(size_t size) {
   return Result::Ok;
 }
 
-Result MemoryAllocStream::WriteDataImpl(size_t dst_offset,
-                                        const void* src,
-                                        size_t size) {
-  if (size == 0) {
-    return wabt::Result::Ok;
-  }
-  size_t end = dst_offset + size;
-  bool needRealloc = false;
-  while (end > total_size) {
-    total_size = total_size << 1;
-    needRealloc = true;
-  }
-  if (needRealloc) {
-    output_data = static_cast<uint8_t*>(realloc_fn(output_data, total_size));
-  }
-
-  if (end > used_size) {
-    used_size = end;
-  }
-
-  memcpy(output_data + dst_offset, src, size);
-  return wabt::Result::Ok;
-}
-
-Result MemoryAllocStream::MoveDataImpl(size_t dst_offset,
-                                       size_t src_offset,
-                                       size_t size) {
-  if (size == 0) {
-    return wabt::Result::Ok;
-  }
-  size_t src_end = src_offset + size;
-  size_t dst_end = dst_offset + size;
-  size_t end = src_end > dst_end ? src_end : dst_end;
-
-  bool needRealloc = false;
-  while (end > total_size) {
-    total_size = total_size << 1;
-    needRealloc = true;
-  }
-  if (needRealloc) {
-    output_data = static_cast<uint8_t*>(realloc_fn(output_data, total_size));
-  }
-
-  if (end > used_size) {
-    used_size = end;
-  }
-
-  uint8_t* dst = output_data + dst_offset;
-  uint8_t* src = output_data + src_offset;
-  memmove(dst, src, size);
-  return wabt::Result::Ok;
-}
-
-Result MemoryAllocStream::TruncateImpl(size_t size) {
-  if (size > used_size) {
-    return wabt::Result::Error;
-  }
-  used_size = size;
-
-  // will not truncate size, we can truncate it at end
-  // output_data = (uint8_t*)realloc_fn(output_data, size);
-  // total_size = size;
-  return wabt::Result::Ok;
-}
-
 FileStream::FileStream(std::string_view filename, Stream* log_stream)
     : Stream(log_stream), file_(nullptr), offset_(0), should_close_(false) {
   std::string filename_str(filename);